A static projective control method of a flying-wing UAV based on the robust and optimal theories

Abstract

According to the unusual conformation and aerodynamic characteristic of a flying-wing UAV, a static projective control system is designed based on the robust and optimal theories. Firstly the features of a flying-wing UAV are presented and a 6 DOF (degree of freedom) nonlinear model of the aircraft is given. Secondly the static projective control method is formulated in three parts: (1) modeling of an expanded robust-servo system; (2) applying the LQR (Linear Quadratic Regulator) method of optimal control to the robust-servo system; (3) using the static projective law to reconstruct the closed loop system by output feedback as a substitute for LQR state feedback. After that an example of a particular static projective controller designing is presented. In simulation, a trajectory tracking example is given by adding additional outer loop controllers outside the static projective controllers. The characteristics of the static projective controllers are shown by a comparison with the ordinary PID attitude autopilot. Then a satisfactory trajectory tracking result is shown which indicates the excellent transient performance and accuracy of static projective controllers of the inner loops.